This project explores the relationship among conflict, control, and reward three psychological constructs that we believe play pivotal roles in the mediation of adaptive adjustments in behavior in response to environmental inputs. We use behavioral, functional neuroimaging, and pupillometric methods to study a number of cognitive tasks that elicit response conflict and recruitment of control. Because of the dynamical complexities inherent in such cognitive processes, our predictions and analyses will be informed by the dynamical systems analysis and computational modeling work of the Center. Our first objective is to examine how conflict induces the recruitment of control. fMRI studies will aid in exploring the neural bases of conflict detection and deployment of control. We predict that anterior cingulate cortex (ACC) will activate proportionally with response conflict, while the allocation of control will be associated with activation elsewhere (e.g., prefrontal cortex). A second objective is to determine whether the prospect of reward modulates tolerance for conflict and subsequent deployment of control. Specifically, we hypothesize that more highly-rewarding tasks will lead to greater tolerance of conflict and larger allocation of control. Behavioral data will be collected using response-conflict and decision-making tasks in which reward and conflict are experimentally manipulated. Functional imaging will test hypotheses regarding the brain mechanisms involved in the modulating effects of reward. The third objective is to implement pupillometry as a potential index of locus coeruleus activity. We hypothesize that the LC exhibits differential modes of activity corresponding to different control sites. Following primate neurophysiologic studies correlating LC activity with pupil size, we will collect human pupillometric data as a potential non-invasive measure of LC-mediated control state. fMRI will be used to determine whether LC activity can be reliably visualized via functional imaging.